Tips & tricks for Ubuntu

Fixing Bugs

Kristian Kissling

In this article, we'll show you how to deal with some possible errors in Ubuntu that might affect suspend mode and Unity.

Intel: Dealing with the Suspend Bug

Intel users often run into an annoying bug: When you shut the laptop cover, the machine falls into a light sleep, from which it should theoretically awaken as soon as you open the cover again; however, some computers, especially those with Intel graphics, will hiccup, resulting in a black or frozen screen. This problem is well known to developers [1].

You don't necessarily need to restart the computer to fix the problem. Switching to a virtual terminal (VT) and giving the LightDM display manager a nudge is often enough. Unfortunately, doing so clears the current desktop session of all the open windows.

To access the VT, press Ctrl+Alt+F1, which takes you to a black-and-white screen with a login prompt. On some keyboards, you also need to press the Fn function key to get to the F1 key. Next, you can log in with your user credentials and enter the following to reanimate the display manager:

$ sudo service lightdm restart

If all goes according to plan, you'll end up on the graphical login screen to the desktop. If you get an error message, you might still be using the old gdm display manager. In this case, replace lightdm with gdm in the sudo service command to get the desired result.

In some cases, the problem seems to go away if you uninstall the gnome-screensaver package, but, then screen locking goes away. You can compensate for that by installing the OpenGL xlockmore-gl screen lock with screensaver package. Then you can use the xlock command to execute the program (Figure 1). This approach is not a guarantee for perpetual peace, but it should help until developers solve the suspend riddle.

Figure 1: The "xlockmore-gl" package conjures up OpenGL images on the screen and blocks with a password. Thus, it can be used as a substitute for Gnome's screensaver.

Unity: Revealing Hidden Applications

Some Unity applications are like scared rabbits that occasionally disappear entirely from the radar screen and can't be reached via Alt+Tab; among these is LibreOffice. Sometimes the LibreOffice start icon disappears from the launcher, leaving an empty space. Although a few methods deal with this problem, I'll look at two of them.

The first approach is to press Super+W to display all the open windows (Figure 2) so that you can access and use the LibreOffice window as usual. Because you need to repeat this method each time you switch to another program, you might want to check whether the following method will work better for you. Minimize the LibreOffice window and right-click the window panel to select Move to Workspace Right to move LibreOffice to the new workspace. As a shortcut, you can press Alt+Ctrl+Right arrow. To return the application to the original desktop, press Alt+Ctrl+Left arrow.

Figure 2: With a trick, you can get your office documents back if they take off into another dimension.